Changes how window manager obtains WindowTree from mus

components/mus/ws/window_tree_binding.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_MUS_WS_WINDOW_TREE_BINDING_H_
 #define COMPONENTS_MUS_WS_WINDOW_TREE_BINDING_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "components/mus/public/interfaces/window_tree.mojom.h"
 #include "mojo/public/cpp/bindings/binding.h"
 
 namespace mus {
 namespace ws {
 
 class WindowServer;
 class WindowTree;
 
-// WindowTreeBinding manages the binding between a WindowTree and its mojo
-// clients. WindowTreeBinding exists so that the client can be mocked for
-// tests. WindowTree owns its associated WindowTreeBinding.
+// WindowTreeBinding manages the binding between a WindowTree and its
+// WindowTreeClient. WindowTreeBinding exists so that a mock implementation
+// of WindowTreeClient can be injected for tests. WindowTree owns its
+// associated WindowTreeBinding.
 class WindowTreeBinding {
  public:
   explicit WindowTreeBinding(mojom::WindowTreeClient* client);
   virtual ~WindowTreeBinding();
 
   mojom::WindowTreeClient* client() { return client_; }
 
   // Obtains a new WindowManager. This should only be called once.
   virtual mojom::WindowManager* GetWindowManager() = 0;
 
@@ skipping 29 matching lines @@
   mojom::WindowTreeClientPtr client_;
   mojom::WindowManagerAssociatedPtr window_manager_internal_;
 
   DISALLOW_COPY_AND_ASSIGN(DefaultWindowTreeBinding);
 };
 
 }  // namespace ws
 }  // namespace mus
 
 #endif  // COMPONENTS_MUS_WS_WINDOW_TREE_BINDING_H_